Microwave Magnetoelectric Effect in a Two-Layer FeGaB/PZN-PT Structure

In connection with the development of spintronics, interest in the magnetoelectric effect in nanostructures has increased. Relatively recently, the magnetoelectric effect in multiferroics in the terahertz range based on various manganites was studied. It is of interest to study the magnetoelectric effect in the FMR region in nanostructures based on ferromagnetic materials. This paper presents the results of investigations of the features of FMR in a thin film (Fe
₈₀
Ga
₂₀
)
₈₈
B
₁₂
(film thickness ~ 100 nm). The values of the resonant magnetizing field are calculated for a frequency of 10 GHz for different orientations of this field. For the case when the bias field is directed perpendicular to the plane of the thin film of the ferromagnet, its resonance value is 17.5 kOe. When the bias field is directed in the plane of the thin film of the ferromagnet along or perpendicular to the easy magnetization axis, its resonance value is 836 Oe and 884 Oe, respectively. The main attention is paid to the theoretical study of a two-layer magnetoelectric composite, in which a (011) cut 0.94PZN - 0.06PT 0.5 mm thick is used as a piezoelectric, on which a thin FeGaB film is deposited. When such a magnetoelectric composite is exposed to a constant electric field directed perpendicular to the plane of the piezoelectric, a shift of the FMR resonance line in a thin ferromagnet film occurs as a result of the microwave magnetoelectric effect. As a result of the calculation, it was found that the shift of the FMR line in the galfenol film with boron in an electric field of 5 kV/cm was 63 Oe for a magnetizing field perpendicular to the film plane. In the case of a bias field directed in the film plane along or perpendicular to the easy magnetization axis, the shift was 166 Oe and 173 Oe, respectively. The calculated shifts of the FMR line are rather large in comparison with the width of the FMR line in the (Fe
₈₀
Ga
₂₀
)
₈₈
B
₁₂
thin film, which is 20 Oe. This makes it possible to confidently observe these shifts. The investigated effect can find practical application in the development of spintronic microwave devices.